HIV-associated neurocognitive disorders (HAND) remain prevalent despite the use of antiretroviral therapy (ART), and CNS inflammation & neurodegeneration associated with HIV replication in macrophages/microglia remain as neuropathological features. Persistent systemic inflammation & monocyte activation, CNS inflammation, macrophage activation, correlate with HAND in patients on ART. Thus, although ART is the backbone of HIV therapy, there is a critical need for adjunctive therapies to suppress persistent inflammation and virus replication, and to decrease the high burden of HAND- associated disability. Accordingly, drugs that suppress inflammation and HIV replication systemically and within the CNS are especially attractive as adjunctive neuroprotectants. We are proposing a dual-investigator MPI study (Kolson, Aldvoni) to investigate a novel drug, dimethyl fumarate, (DMF, Fumaderm(R)), now in a phase III clinical trial for multiple sclerosis) as a candidate neuroprotectant for HAND. Using our HIV neurotoxicity model we found that DMF and its primary in vivo metabolite, MMF, suppress a) HIV replication, b) associated inflammatory responses, and c) neurotoxin production in monocyte- derived macrophages (MDM). DMF/MMF also d) induces monocyte antioxidant responses and e) suppresses chemotaxis. In addition, using transcriptome analyses of HIV-infected T lymphocytes and MDM, we also demonstrated that HIV reprograms host gene expression in a cell-dependent manner to modulate pathways of virus spread, inflammatory mediators, and apoptosis, which can intersect pathways of HIV/MDM neurotoxin production & neurodegeneration. Because DMF is orally-deliverable, CNS- penetrating, and minimally toxic, we hypothesize that DMF can be an effective neuroprotectant in HAND and we further hypothesize that transcriptome analyses can identify host pathways modified by DMF/MMF that underlie its neuroprotection. We will: 1) Define mechanisms of DMF/MMF suppression of HIV replication and MDM neurotoxin production by HIV replication and Tat expression~ 2) Define DMF/MMF effects on suppression of monocyte & macrophage activation through anti-oxidant responses & other pathways~ 3) Determine mechanisms of DMF/MMF modulation of monocyte chemotaxis & transendothelial migration~ and 4) Determine the ability of DMF/MMF to suppress monocyte activation and induce antioxidant responses in SIV-infected rhesus macaques. This should provide a rationale for a future clinical trial in HIV patients.